First-ranked cluster galaxies - A two-population model

Abstract

view Abstract Citations (25) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS First-ranked Cluster Galaxies: A Two-Population Model Bhavsar, Suketu P. Abstract The small dispersion in the absolute magnitudes (~ 0.35 mag) of first-ranked galaxies in rich clusters has been the cause for much debate between the "special" and "statistical" hypotheses for these galaxies. We present statistical evidence that it is not the one or the other but a combination. The distribution in magnitudes of the brightest galaxies is best explained if they consist of two distinct populations of objects; a population of special galaxies having a Gaussian distribution of magnitudes with a small dispersion (0.21 mag), and a population of extremes of a statistical luminosity function. The best fit model requires that 63% of the clusters have a special galaxy that is, on average, 0.48 mag brighter than the brightest normal galaxy. The model also requires the luminosity function of galaxies in clusters to be much steeper at the very tail end than conventionally described. Publication: The Astrophysical Journal Pub Date: March 1989 DOI: 10.1086/167229 Bibcode: 1989ApJ...338..718B Keywords: Astronomical Photometry; Computational Astrophysics; Galactic Clusters; Astronomical Models; Brightness Distribution; Electrophotometers; Astrophysics; GALAXIES: CLUSTERING; GALAXIES: PHOTOMETRY; LUMINOSITY FUNCTION full text sources ADS |